Add Faces

crates/fj-kernel/src/algorithms/transform.rs

@@ -106,14 +106,20 @@ impl TransformObject for GlobalVertex {
 
 impl TransformObject for Shell {
     fn transform(self, transform: &Transform) -> Self {
-        let faces = self.into_faces().map(|face| face.transform(transform));
+        let faces = self
+            .into_faces()
+            .into_iter()
+            .map(|face| face.transform(transform));
         Self::new().with_faces(faces)
     }
 }
 
 impl TransformObject for Sketch {
     fn transform(self, transform: &Transform) -> Self {
-        let faces = self.into_faces().map(|face| face.transform(transform));
+        let faces = self
+            .into_faces()
+            .into_iter()
+            .map(|face| face.transform(transform));
         Self::new().with_faces(faces)
     }
 }

crates/fj-kernel/src/objects/face.rs

@@ -1,10 +1,49 @@
+use std::collections::{btree_set, BTreeSet};
+
 use fj_interop::mesh::Color;
 use fj_math::Triangle;
 
 use crate::builder::FaceBuilder;
 
 use super::{Cycle, Surface};
 
+/// A collection of faces
+#[derive(Clone, Debug, Default, Eq, PartialEq, Hash, Ord, PartialOrd)]
+pub struct Faces {
+    inner: BTreeSet<Face>,
+}
+
+impl Faces {
+    /// Create an empty instance of `Faces`
+    pub fn new() -> Self {
+        Self::default()
+    }
+}
+
+impl Extend<Face> for Faces {
+    fn extend<T: IntoIterator<Item = Face>>(&mut self, iter: T) {
+        self.inner.extend(iter)
+    }
+}
+
+impl IntoIterator for Faces {
+    type Item = Face;
+    type IntoIter = btree_set::IntoIter<Face>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.inner.into_iter()
+    }
+}
+
+impl<'a> IntoIterator for &'a Faces {
+    type Item = &'a Face;
+    type IntoIter = btree_set::Iter<'a, Face>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.inner.iter()
+    }
+}
+
 /// A face of a shape
 #[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub struct Face {

crates/fj-kernel/src/objects/mod.rs

@@ -18,7 +18,7 @@ pub use self::{
     curve::{Curve, CurveKind, GlobalCurve},
     cycle::Cycle,
     edge::{Edge, GlobalEdge, VerticesOfEdge},
-    face::Face,
+    face::{Face, Faces},
     shell::Shell,
     sketch::Sketch,
     solid::Solid,

crates/fj-kernel/src/objects/shell.rs

@@ -1,8 +1,6 @@
-use std::collections::BTreeSet;
-
 use crate::builder::ShellBuilder;
 
-use super::Face;
+use super::{face::Faces, Face};
 
 /// A 3-dimensional closed shell
 ///
@@ -12,7 +10,7 @@ use super::Face;
 /// currently validated.
 #[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub struct Shell {
-    faces: BTreeSet<Face>,
+    faces: Faces,
 }
 
 impl Shell {
@@ -24,7 +22,7 @@ impl Shell {
     /// Construct an empty instance of `Shell`
     pub fn new() -> Self {
         Self {
-            faces: BTreeSet::new(),
+            faces: Faces::new(),
         }
     }
 
@@ -41,13 +39,13 @@ impl Shell {
     }
 
     /// Access the shell's faces
-    pub fn faces(&self) -> impl Iterator<Item = &Face> {
-        self.faces.iter()
+    pub fn faces(&self) -> &Faces {
+        &self.faces
     }
 
     /// Convert the shell into a list of faces
-    pub fn into_faces(self) -> impl Iterator<Item = Face> {
-        self.faces.into_iter()
+    pub fn into_faces(self) -> Faces {
+        self.faces
     }
 }
 

crates/fj-kernel/src/objects/sketch.rs

@@ -1,8 +1,6 @@
-use std::collections::BTreeSet;
-
 use crate::builder::SketchBuilder;
 
-use super::{Face, Surface};
+use super::{face::Faces, Face, Surface};
 
 /// A 2-dimensional shape
 ///
@@ -12,7 +10,7 @@ use super::{Face, Surface};
 /// currently validated.
 #[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub struct Sketch {
-    faces: BTreeSet<Face>,
+    faces: Faces,
 }
 
 impl Sketch {
@@ -24,7 +22,7 @@ impl Sketch {
     /// Construct an empty instance of `Sketch`
     pub fn new() -> Self {
         Self {
-            faces: BTreeSet::new(),
+            faces: Faces::new(),
         }
     }
 
@@ -41,13 +39,13 @@ impl Sketch {
     }
 
     /// Access the sketch's faces
-    pub fn faces(&self) -> impl Iterator<Item = &Face> {
-        self.faces.iter()
+    pub fn faces(&self) -> &Faces {
+        &self.faces
     }
 
     /// Convert the sketch into a list of faces
-    pub fn into_faces(self) -> impl Iterator<Item = Face> {
-        self.faces.into_iter()
+    pub fn into_faces(self) -> Faces {
+        self.faces
     }
 }
 

crates/fj-operations/src/lib.rs

@@ -68,6 +68,7 @@ impl Shape for fj::Shape {
                 .compute_brep(config, tolerance, debug_info)?
                 .into_inner()
                 .into_faces()
+                .into_iter()
                 .collect::<Vec<_>>()
                 .validate_with_config(config),
             Self::Group(shape) => {